Today I went small mammal trapping in Stockport with the Greater Manchester Ecology Unit. It was a morning collection, so we were picking up the contents of traps laid out last night. Sadly I wasn't able to help out yesterday due to teaching on my only Thursday all year. This was double sadly as I'd also been offered both an evening and a morning bat survey by a firm, but so it goes. Keep on swimming...
The traps that we were using were humane traps -- Longworths to be precise. It's been some time since I used them, but they're awesome little things. They don't hurt the little critters at all as long as you stock up the trap with a good deal of food and warmth, which is precisely the kind of thing that these creatures are after in the first place. The traps look like this:
They come complete with a little door and everything. The mammal survey at Etherow was two transects of 20 traps set at 10m intervals. The first transect was near a field margin and had largely been disturbed by either dogs or badgers -- both were really likely in that part of the woods. We did manage to get our hands on one that wasn't disturbed and that had caught a woodmouse (Apodemus sylvaticus). In order to get a good looksee, you have to dump the trap into a plastic bag, which gives you a confused looking mouse, looking up at you:
On this survey, we were recording the state of the trap (disturbed, open, closed); what, if anything, we caught; mortality and any other notes (juvenile/adult, gender). We also took hair samples from the mice for DNA analysis for a study of genetic drift in populations of mice.
The second transect, which was up in more dense woodland and off a path, yielded more variety as we also found bank voles. These chaps are a far more reddy brown than woodmice. They've also got smaller ears by comparison and have (I think) a blunter, less refined muzzle. We caught a juvie (so small!):
And we shall call him Bitey, because that's exactly what he did to the lass who was holding him.
We also caught and sexed a couple of others, which were mostly male. Apparently, if you hold them a certain way, the vole stops struggling and you can tell it's gender:
And this one I shall call Peevish, because he looks not only indignant, but peeved.
We didn't catch any shrews, which is a first for me, but also makes me quite happy. Shrews have such a fast metabolism that unless you cram the trap with food and rescue it sharpish, they starve to death. In fact, they can die of starvation in only 5 hours as they need to eat up to 300% of their own body weight every day. To do this, they must eat every 2-3 hours. That's one hell of a downside, but they do eat everything and anything -- including canned hotdog sausages.
Canned hotdog sausages are great bait for hedgehog traps. These traps don't trap the animal, but they do attract them and cause them to walk through either ink or some kind of paw print capturing surface for ID purposes. The trap below used a mixture of ink and washing up liquid, with paper to capture prints and a hotdog as bait:
These traps were laid out as one transect of 10 traps, along the edge of a path, with one trap every 100m. We think that the first trap may have had a shrew in it, but that's only a maybe based on paw prints and teeth marks. We also found evidence of bank voles and woodmice in the other traps -- did I mention that I can now ID rodent poo? Well, I can now for these two species. We also found slugs in some of the traps as well as evidence that one of the little critters had pulled the hotdog out of the trap and off somewhere. Inky dragmarks are a dead giveaway!
Sadly, we saw no evidence of hedgehogs. I do not know if this is normal for this site, but I do know that hedgehogs are in decline but no one really knows how much by. Here's hoping that either they went to ground last night or that they just never really liked that site.
All in all, it was a really interesting and productive day. Incidentally, Etherow had a diverse amount of fungi about, so it's well worth a further investigation.
The traps that we were using were humane traps -- Longworths to be precise. It's been some time since I used them, but they're awesome little things. They don't hurt the little critters at all as long as you stock up the trap with a good deal of food and warmth, which is precisely the kind of thing that these creatures are after in the first place. The traps look like this:
(Image from University of Aberdeen as I forgot to snap one...)
They come complete with a little door and everything. The mammal survey at Etherow was two transects of 20 traps set at 10m intervals. The first transect was near a field margin and had largely been disturbed by either dogs or badgers -- both were really likely in that part of the woods. We did manage to get our hands on one that wasn't disturbed and that had caught a woodmouse (Apodemus sylvaticus). In order to get a good looksee, you have to dump the trap into a plastic bag, which gives you a confused looking mouse, looking up at you:
On this survey, we were recording the state of the trap (disturbed, open, closed); what, if anything, we caught; mortality and any other notes (juvenile/adult, gender). We also took hair samples from the mice for DNA analysis for a study of genetic drift in populations of mice.
The second transect, which was up in more dense woodland and off a path, yielded more variety as we also found bank voles. These chaps are a far more reddy brown than woodmice. They've also got smaller ears by comparison and have (I think) a blunter, less refined muzzle. We caught a juvie (so small!):
And we shall call him Bitey, because that's exactly what he did to the lass who was holding him.
We also caught and sexed a couple of others, which were mostly male. Apparently, if you hold them a certain way, the vole stops struggling and you can tell it's gender:
And this one I shall call Peevish, because he looks not only indignant, but peeved.
We didn't catch any shrews, which is a first for me, but also makes me quite happy. Shrews have such a fast metabolism that unless you cram the trap with food and rescue it sharpish, they starve to death. In fact, they can die of starvation in only 5 hours as they need to eat up to 300% of their own body weight every day. To do this, they must eat every 2-3 hours. That's one hell of a downside, but they do eat everything and anything -- including canned hotdog sausages.
Canned hotdog sausages are great bait for hedgehog traps. These traps don't trap the animal, but they do attract them and cause them to walk through either ink or some kind of paw print capturing surface for ID purposes. The trap below used a mixture of ink and washing up liquid, with paper to capture prints and a hotdog as bait:
These traps were laid out as one transect of 10 traps, along the edge of a path, with one trap every 100m. We think that the first trap may have had a shrew in it, but that's only a maybe based on paw prints and teeth marks. We also found evidence of bank voles and woodmice in the other traps -- did I mention that I can now ID rodent poo? Well, I can now for these two species. We also found slugs in some of the traps as well as evidence that one of the little critters had pulled the hotdog out of the trap and off somewhere. Inky dragmarks are a dead giveaway!
Sadly, we saw no evidence of hedgehogs. I do not know if this is normal for this site, but I do know that hedgehogs are in decline but no one really knows how much by. Here's hoping that either they went to ground last night or that they just never really liked that site.
All in all, it was a really interesting and productive day. Incidentally, Etherow had a diverse amount of fungi about, so it's well worth a further investigation.
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